Princess Diana has angered government ministers after calling for an international ban on landmines.

Her comments - made during a visit to Angola to see for herself some of the victims of landmines - are being seen as out of step with government policy.

The Junior Defence Minister, Earl Howe, has described the princess as a "loose cannon", ill-informed on the issue of anti-personnel landmines.

Although he is now seeking to distance himself from the criticism, other Conservative backbenchers have been more outspoken.

Peter Viggers, Tory member of the defence select committee, said: "We all know landmines and other weapons are vicious and nasty. The question is how best to negotiate so they are not used in future.

"The government's policy on this has been an extremely careful one and the statements made by the Princess of Wales have not been in line with that policy."

The government is involved in international negotiations for a worldwide ban on landmines, but in the meantime the army is still using them.

The princess has insisted the row over her comments is a distraction and all she was trying to do was help.

She is in Angola as a guest of the International Red Cross, which has been pressing for a landmine ban.

Labour has welcomed the intervention by the princess. It is backing calls for an international moratorium on the use of anti-personnel mines.

Shadow defence spokesman, David Clark, said: "I think we should all welcome the fact she has gone to Angola and she has tried to warn the world of the dangers of these terrible weapons. I think we should be applauding what she's doing."